Sheets ejected from an image forming apparatus such as a copying machine, a laser beam printer or the like sometimes need to be stamped with "SECRET", "CIRCULAR NOTICE" etc. Various types of sheet handling apparatus having a stapling function and various types of stamping means for stamping on copying paper have been ever commercialized. The Japanese Patent Laid Open Publication No. 55-15150 discloses a copying machine wherein a stamp is arranged behind a fixing device therein to stamp on sheets of copying paper at the position automatically.
However, conventionally, since the stapling operation and the stamping operation have been performed by different devices, separate spaces for the different devices have been needed, and the effective use of space has not been made. Also, if sheets are stamped while being transported, the position to be stamped at may be skewed owing to the skew of the sheets, and a paper jam may be caused. Further, if a stamping function is just added to a conventional sheet handling apparatus having a stapling function, a driving device for the stamping function has to be disposed separately, and the copying operation may have to be interrupted while the stamping function is performed.